WASHINGTON — A House panel approved legislation Wednesday that slashes in half the amount of offshore areas protected from oil and gas drilling, while providing states lucrative financial inducements to voluntarily surrender their coastlines to exploration and development.

The action by the House Resources Committee came on a measure cobbled together by its chairman, Rep. Richard Pombo, R-Calif., who just a year ago was telling reporters that he supported the moratoria on drilling in federal waters that he denounced Wednesday.

The Pombo bill cleared the committee on a 29-9 vote. It heads to the House floor next week, where it is expected to pass. But from there, the bill heads into legislative limbo. There is no similar legislation in the Senate and most think there is little interest in it.

Congress has banned offshore drilling along the East and West coasts for 25 years; President George H.W. Bush continued the ban by executive order through 2012. U.S. jurisdiction extends 200 miles from the coastline.

The Pombo bill would immediately end the ban in waters from 100 miles to 200 miles out, which off California is too deep for drilling anyway.

For waters from the coast out to 50 miles, the drilling ban would be made permanent but states would have terrific incentives starting at 75 percent of the revenues to opt out and let the drilling rigs in. That is where most of the development potential is off the California coast.

In the waters between 50 and 100 miles from the coastline, the legislation forces state legislatures to vote regularly for the ban to remain in place. As it applies to natural gas drilling, the vote would have to occur within a year of the bill’s passage. The measure gives states three years to deliberate on whether to permit oil drilling, but in both instances the state would have to act again in five years or the ban would expire.

Pombo said in bringing the bill to a vote Wednesday the measure strikes “an equitable balance between conservation and the common-sense necessities of our economy.”

The Bush administration put Pombo on notice that it opposes the money drain caused by the rich incentives for the states.

“Our preliminary and very rough estimates indicate that these provisions, if unchanged, would result on a decline of $69 billion of retained federal royalties over 15 years,” the head of the Minerals Management Service, R.M. Johnnie Burton, told Pombo in a letter Wednesday. “This diversion would have significant impacts on the federal debt.”

The bill, at least in the short run, would have little practical consequence in California because of geography.

The outer continental shelf — that area of relatively shallow coastal waters that can be easily drilled with current technology — is narrow along almost all the state’s entire coastline, and is narrowest in northern parts of the state. Beyond the shelf, the ocean floor falls rapidly to depths of nearly two miles.

According to a 1999 report of the Minerals Management Service, the California coastline contains an estimated 408 million barrels and 1.2 trillion cubic feet of known reserves. Unproven reserves are estimated at another 1.3 million barrels of oil and 922 billion cubic feet of gas.

Pombo said in a brief interview after the vote, however, that he doesn’t see the state legislature voting to develop those reserves.

“I don’t think it will have any impact on California at all,” Pombo said of the legislation in a brief interview after the committee meeting. “California controls the first 100 miles, and beyond that the water is too deep.”